Mantaflow smoke looks a bit weird
Did you read the comments? Often people write problmes + solutions in the comments.
So next questions:
Did you use Cycles?
Did you bake?
Did you see that comment here:
NOTE TO NOOBS LIKE ME AND ANYBODY ATTEMPTING THE TUTORIAL - when Olav says the word &quot;flame&quot; is important, he actually is referring to how it's typed, not just what is typed.
DONT USE CAPS! Took me forever to realize it's like an input term, not a name, and effects the results it must be written as &quot;flame&quot; or it won't be recognized as the intended value. I had F capitalized.  The attribute flame won't work right if typed in any other way.

...and...what i made wrong often: every little step in the tutorial, do it exactly how the teacher does it, else everything can happen. I often did thing slightly different which looked the same in that moment, but weren't the same. E.g. if you move your cube in object mode with G, it is something totally different to move your cube in edit mode!!! Because the origin point changes! Took me quite a while to understand this &quot;little&quot; differeence...